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dc.contributor.author엄익환-
dc.date.accessioned2016-08-28T10:08:03Z-
dc.date.available2016-08-28T10:08:03Z-
dc.date.issued2013-
dc.identifier.issn0253-2964-
dc.identifier.otherOAK-10143-
dc.identifier.urihttp://dspace.ewha.ac.kr/handle/2015.oak/223773-
dc.description.abstractPseudo-first-order rate constants (kobsd) have been measured spectrophotometrically for the nucleophilic substitution reactions of 2-pyridyl thionobenzoate (5b) with alkali-metal ethoxides (EtOM, M+ = Li +, Na+, K+, and 18-crown-6-ether complexed K+) in anhydrous ethanol at 25.0 ± 0.1 oC. The plots of kobsd vs. [EtOM]o curve upward regardless of the nature of the M+ ions, while those of kobsd/[EtO -]eq vs. [EtO-]eq are linear with a positive intercept. Dissection of kobsd into kEtO- and kEtOM (i.e., the second-order rate constants for the reactions with the dissociated EtO- and ion-paired EtOM, respectively) has revealed that the ion-paired EtOM is more reactive than the dissociated EtO-, and M+ ions catalyze the reactions in the order K+ Na + Li+ 18C6-complexed K+. The plot of log k EtOM vs. 1/rStokes results in an excellent linear correlation, indicating that the reactions are catalyzed by the solvated M + ions but not by the bare M+ ions. The reactions of 5b with EtOM have been concluded to proceed through a six-membered cyclic TS, in which the solvated M+ ions increase the electrophilicity of the reaction center and the nucleofugality of the leaving group.-
dc.languageEnglish-
dc.titleMetal-ion catalysis in alkaline ethanolysis of 2-pyridyl thionobenzoate: Effects of modification of electrophilic center from C=O to C=S-
dc.typeArticle-
dc.relation.issue5-
dc.relation.volume34-
dc.relation.indexSCI-
dc.relation.indexSCIE-
dc.relation.indexSCOPUS-
dc.relation.indexKCI-
dc.relation.startpage1525-
dc.relation.lastpage1529-
dc.relation.journaltitleBulletin of the Korean Chemical Society-
dc.identifier.doi10.5012/bkcs.2013.34.5.1525-
dc.identifier.wosidWOS:000319710400040-
dc.identifier.scopusid2-s2.0-84878071720-
dc.author.googleUm I.-H.-
dc.author.googleSong Y.-J.-
dc.author.googleKim M.-Y.-
dc.author.googleLee J.-I.-
dc.contributor.scopusid엄익환(7006725706;6506759437)-
dc.date.modifydate20180104081001-
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자연과학대학 > 화학·나노과학전공 > Journal papers
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